A plurality of applications requiring resting or anchoring to the ground are known in the fields of building, installation in general, hobby, sport, agricultural.
For example, such anchoring requirement can be found in garden articles such as gazebo, spotlights and others, in sporting field with ropes or tension rods for tents, or also in road field for supporting signs or baskets in public areas, in private building for photo-electric cells and motors of electric gates.
Always as an example, other products requiring a ground anchoring are both advertising and traffic road signs or photovoltaic panels.
In case of anchoring structures with high loads, sometimes also for simple posts, on various kind of natural grounds, when the mere vertical driving is not sufficient, concrete casting both armoured and not are used. This casting, also called foundation plinth, into which log bolts or various kind of insert opposing to the mechanical loads exerted by the structure resting thereon, is characterized by their complexity and by the application time. In fact, these systems requires an excavation followed by material casting, that will be suitable for anchoring only after it has hardened.
Among the most felt evident problems during the realization of the hereby described anchorage on this kind of grounds, there is the difficulty in optimizing the stability of the anchored structure. The ground is often subjected to settling as it has been removed in order to obtain the anchoring site and restored upon completed anchorage. In any case in each of the previously described methods, both patented and not, a system which is sequentially removable and successively even reusable has been never disclosed. Last, but probably even more relevant there is the installation cost of the above mentioned systems, cost determined by installation times and by the required labour.
Other anchoring techniques which do not require excavation and cementing exist, which substantially consists of driving posts, screw system, variously shaped and sized anchors in the ground with mechanical or manual systems. With reference to posts and screw systems, although being an effective solution when loads and mechanical forces urging on the structure are not particularly severe, they have remarkable limits concerning the resistance to traction. In fact, their resistance is determined only by the pressure exerted by the material into which they are driven against the wall of the object itself. Accordingly, the lateral shaking of the post remarkably reduces the anchorage strength. The system with an anchor buried deep in the ground somehow overcome this problem, even if it is less effective in withstanding lateral and vertical pressures exerted on the supported structure and it is also particularly expensive in its realization and limited in being applicable only for resistance to traction. All the above mentioned system are sensitive to the variations of the ground compaction conditions and to the driving-in depth. Patent literature offers several examples also in this case, such as the Italian patent IT 1177338 to Sistemi Chiocciola S.r.1. Nevertheless, the screw system driving in the ground has some problems during installation as the screw could go down with a certain tilting without allowing a perfect verticality to the ground of the structure that will support, as long as particularly complex machineries are used. Moreover, in the case of rocky bottom this kind of system cannot be installed and also the above mentioned ones could be installed with great difficulties at least without a preliminary perforation of a certain amount.
As an alternative to such systems also anchoring systems exist that envisage the installation of a supporting structure to the object to be anchored, the former being fixed to the ground by means of rods to be inserted tilted in the ground through apposite guides.
One example of such system is described in U.S. Pat. No. 2,826,281, using a ring to be fixed around a post onto which a set of rods can be inserted, that are driven in the ground, through apposite guides.
Nevertheless, this solution does not provide sufficient stability to the structure and, in fact, requires the use of a concrete casting in connection to the rods for maintaining stabile the structure.
Moreover, also in this case, the system requires a excavation step, with a consequent placing of the structure beneath ground, thus making the installation difficult. In general, moreover, the employed guides have excessively shorts dimension allowing to drive the rods only according to a limited tilting, without offering any structural stiffness. In fact, in confirmation of this, it can be noted that the structure should be necessary buried in a concrete casting, or it does not provide sufficient stability.
As an alternative to such system, the European patent EP 483 158, also relative to the use of tilted rods for anchoring an object to the ground, describes the use of elongated stones provided with staggered holes for guiding the rods. On the contrary, in this case the presence of the holes is critical as the risk of excessively inserting the rod in the hole, thus passing over it, exists, compromising the guiding function normally achieved by the pair of holes. Moreover, the rods can also pass over during the use of the anchoring system, i.e. after the installation thereof, as lateral oscillations of the anchored object could produce small movements in the rods that, in the long run, would cause the passing over thereof. According to an alternative embodiment, the patent describes the use of posts provided with a series of through holes, into which inserting the rods, that can be directly inserted in the ground. Nevertheless, in this case the structure is hardly suitable for fixing small objects and, moreover, it necessary requires a preliminary working of the object to be anchored.